Citric Acid Metabolism in Resistant Hypertension Underlying Mechanisms and Metabolic Prediction of Treatment Response

• Published in: Hypertension (Dallas, Tex. 1979) Vol. 70; no. 5; pp. 1049 - 1056
• Main Authors: Martin-Lorenzo, Marta, Martinez, Paula J., Baldan-Martin, Montserrat, Ruiz-Hurtado, Gema, Prado, Jose Carlos, Segura, Julian, de la Cuesta, Fernando, Barderas, Maria G., Vivanco, Fernando, Ruilope, Luis Miguel, Alvarez-Llamas, Gloria
• Format: Journal Article
• Language: English
• Published: United States 01.11.2017
• Subjects: Aged; Antihypertensive Agents - administration & dosage; Antihypertensive Agents - adverse effects; Antihypertensive Agents - pharmacokinetics; Chromatography, Liquid - methods; Citric Acid - analysis; Citric Acid - metabolism; Drug Resistance - physiology; Drug-Related Side Effects and Adverse Reactions - diagnosis; Drug-Related Side Effects and Adverse Reactions - urine; Female; Humans; Hypertension - drug therapy; Hypertension - epidemiology; Hypertension - metabolism; Ketoglutaric Acids - analysis; Ketoglutaric Acids - metabolism; Male; Middle Aged; Predictive Value of Tests; Prognosis; Spain - epidemiology; Spironolactone - administration & dosage; Spironolactone - adverse effects; Spironolactone - pharmacokinetics; Urinalysis - methods; blood pressure; citric acid cycle; metabolomics; spironolactone; reactive oxygen species
• ISSN: 0194-911X; 1524-4563; 1524-4563
• DOI: 10.1161/HYPERTENSIONAHA.117.09819

Resistant hypertension (RH) affects 9% to 12% of hypertensive adults. Prolonged exposure to suboptimal blood pressure control results in end-organ damage and cardiovascular risk. Spironolactone is the most effective drug for treatment, but not all patients respond and side effects are not negligible. Little is known on the mechanisms responsible for RH. We aimed to identify metabolic alterations in urine. In addition, a potential capacity of metabolites to predict response to spironolactone was investigated. Urine was collected from 29 patients with RH and from a group of 13 subjects with pseudo-RH. For patients, samples were collected before and after spironolactone administration and were classified in responders (n=19) and nonresponders (n=10). Nuclear magnetic resonance was applied to identify altered metabolites and pathways. Metabolites were confirmed by liquid chromatography-mass spectrometry. Citric acid cycle was the pathway most significantly altered ( P <0.0001). Metabolic concentrations were quantified and ranged from ng/mL malate to μg/mL citrate. Citrate and oxaloacetate increased in RH versus pseudoresistant. Together with α-ketoglutarate and malate, they were able to discriminate between responders and nonresponders, being the 4 metabolites increased in nonresponders. Combined as a prediction panel, they showed receiver operating characteristiccurve with area under the curve of 0.96. We show that citric acid cycle and deregulation of reactive oxygen species homeostasis control continue its activation after hypertension was developed. A metabolic panel showing alteration before spironolactone treatment and predicting future response of patients is shown. These molecular indicators will contribute optimizing the rate of control of RH patients with spironolactone.